Dust removing dquipment for a shuttle race

ABSTRACT

Dust removing equipment on the inside of the shuttle race of a lock stitch sewing machine. The shuttle race has a guide groove to receive the sliding part of the semirotary shuttle, and a driver is provided which reciprocates the shuttle along the shuttle race. A dust remover has a middle part which is fixed to the external center of the driver means, which dust remover is made of an elastic material with a low coefficient of friction. It has knife edges at both ends in contact with the bottom of the guide groove of the shuttle race which are retained by the elasticity of the material.

United States Patent Nishikawa [451 Mar. 21, 1972 54 DUST REMQYINQEQUTPMENZILFQK i 2,842,081 7/1958 Kurihara ..112 192 SHUTTLE RACE 3,374,757 3/1968 Hamlett ..112/196 [72] Inventor: Masataka Nishikawa, Hikone-shi, Japan Primary Examiner H Hampton Hunter [73] Assignee: Chiyoda Sangyo Co., Ltd., Shiga Prefec- Attorn y turc, Japan 22 Filed: Dec. 1, 1969 [57] ABSTRACT Dust removing equipment on the inside of the shuttle race of a [2]] Appl' 881004 lock stitch sewing machine. The shuttle race has a guide groove to receive the sliding part of the semirotary shuttle, F gn App n Priori y Data and a driver is provided which reciprocates the shuttle along Dec. 26 1968 Japan ..43/114028 the Shuttle race- A lemme has a middle Part which is fixed to the external center of the driver means, which dust 52 us. 01 112/192 remover is made of an elastic material with a low coefficient of 51 1 n I I I 05 57/12 friction. It has knife edges at both ends in contact with the hot- [58] Field of Search ..1 12/192, 193, 196, 232 to o the guide g o of the shuttle race h c are retained by the elasticity of the material.

[56] References Cited 3 Claims, 4 Drawing Figures UNITED STATES PATENTS 2,822,773 2/1958 Iranko ..112/192 X DUST REMOVING DQUIPMENT FOR A SHUTTLE RACE This invention relates to dust removing equipment to be provided on the inside of the shuttle race of a lock stitch sewing machine in which a semirotary shuttle is used.

In a lock stitch sewing machine equipped with a semirotary shuttle, the shuttle makes a reciprocating movement, the external periphery thereof being fitted into the internal guide groove of the shuttle race. The sliding part provided on the shuttle covers approximately a semicircle of the guide groove of the shuttle race, the remaining semicircle of the guide groove being constantly exposed.

Consequently, in the course of the operation of the sewing machine the dust is liable to accumulate in guide groove and slip inbetween the sliding part of the shuttle and the guide groove, with the result that the operation lacks smoothness and produces an unpleasant noise.

The first object of the present invention is to provide equipment which automatically removes the dust accumulating in the guide groove of the shuttle race of a lock stitch sewing machine equipped with a semirotary shuttle.

The second object of the invention is to simplify as much as possible the dust removing equipment for the foregoing object so as to facilitate the production and assemblage thereof.

The third object of the invention is to provide dust removing equipment which is highly efficient despite the remarkable simplicity of the construction thereof.

The fourth object of the invention is to provide dust removing equipment which can be easily attached to the conventional lock stitch sewing machine with a semirotary shuttle without any remodeling thereof.

The aforementioned objects and effect of the invention are attainable by the attachment and function of the parts constituting the invention, and the particulars thereof will be described in terms of preferred embodiments with reference to the annexed drawing, in which:

FIG. 1 is an elevation showing the shuttle of the lock stitch sewing machine of the invention as well as the part to which the shuttle race is fixed;

FIG. 2 is a magnified view of the foregoing elevation with a part thereofcut off;

FIG. 3 is a cross-sectional view of the foregoing on a magnified scale;

FIG. 4 is a perspective view showing a part of the foregoing in a disassembled state.

The dust removing equipment of the invention chiefly consists of a dust remover to be connected to a shuttle driver which moves along the inside of the shuttle race.

In the drawing the numeral 11 designates the dust remover made of material which is durable, moderately flexible and has a low coefficient of friction, such as polyethylene, nylon and the like, the numeral 12 designating the shuttle race fixed to the body of the sewing machine as commonly known. A guide groove 13 is formed inside the shuttle race 12, the sliding part 21 formed on the external periphery of the semirotary shuttle being fitted into the said guide groove 13 as shown in FIG. 1.

The numeral 14 designates a driver with which to drive the shuttle, the said driver being fitted into the guide groove 13 with an appropriate space left therebetween. The driver 14 is fixed to the end of the lower shaft 28 fixed to the lower part of the body of the sewing machine, both ends of the driver confronting both ends of the shuttle 20 with an appropriate space left therebetween, both ends of the driver 14 reciprocating both ends of the shuttle 20 as the driver 14 makes a reciprocal movement together with the lower shaft 28, the foregoing function being identical with that of known sewing machines.

The foregoing dust remover 11 has approximately the same width as that of the guide groove 13, both ends thereof being formed into knife edges 15 respectively.

The dust remover 11 is arcuated and has a greater radius than that of the arc of the guide groove 13, the said dust remover 11 being thicker at both ends thereof and thinner toward the middle part thereof.

As shown in FIG. 4, on one side of the middle part of the dust remover 11 are formed a pair of protrusions 16 with a hollow 17 therebetween, a wide protrusion 18 being formed on the other side thereof.

On the outside of the middle part of the driver 14 is positioned an engaging extension 19 which is detachably fittable into the hollow 17 on one side of the middle part of the dust remover 11, a head 22 of greater diameter being formed at the external end of the extension 19. The extension 19 may be replaced by a countersunk screw as indicated in FIG. 3.ln this case, the countersunk screw can be utilized as a fixing screw for a plate spring 23 to be placed on the inside of the driver 14.

If the extension 19 on the outside of the middle part of the driver 14 is engaged with the hollow 17 on one side of the middle part of the dust remover 11, the middle part of the dust remover 11 will be securely held between the head diameter 22 and the middle part of the driver 14, the knife edges 15 at both ends of the dust remover being brought into contact with the bottom of the guide groove 13 respectively as illustrated in FIG. 1.

Since the guide groove 13 is formed in the shape of a shoulder on the internal periphery of the shuttle race, there is a risk of the sliding part 21 of the shuttle leaving the guide groove 13. As shown in FIGS. 1 and 3, therefore, an annular padding metal 24 is applied to one side of the guide groove 13 and fixed to the shuttle race 12 by means of a pair of pressing levers 26 which are pivoted to the shuttle race 12 by axes 25 as indicated in FIG. 1.

As described above, the shuttle 20 and the dust remover 11 are prevented from leaving the groove 13. In case, however, there arises the necessity of detaching the shuttle 20 and the dust remover 11, the shuttle 20 and the dust remover 11 will be as shown in FIG. 2 if the padding metal 24 is removed by opening the levers 26 outward so that the shuttle 20 and the dust remover 11 can be detached without difficulty.

Though not shown in the drawing, a bobbin case containing a thread bobbin is fitted into the shuttle 20, the pawling protrusion on the bobbin case being engaged with a notch 27 of the shuttle race 12 so as to prevent the bobbin case from revolving, this arrangement also being conventional.

In the foregoing equipment, the shuttle 20 is driven by the reciprocation of the driver 14 in accordance with the operation of the sewing machine, the dust remover l1 fixed to the outside of the driver 14 being also driven by the driver 14, the knife edges 15 at both ends of the dust remover 11 thereby sliding under pressure along the bottom of the guide groove 13.

Since the knife edges 15 at both ends of the dust remover l1 slide along the bottom of the guide groove 13 as described above, the dust accumulated in the guide groove 13 is scraped away at each passage of the knife edges 15, the dust being scraped up along the slant of each knife edge 15 and out of the guide groove 13. Since the guide groove 13 is free from dust, the sewing machine can be operated silently with smooth movement of the shuttle 20 and uniform stitches at all times.

Not only is the dust remover 11 of the invention made of moderately elastic material, such as polyethylene, nylon and the like, but it is also arranged so that the middle part thereof is thinner than the ends thereof, with the result that bothv knife edges 15 can be pressed against the bottom of the guide groove 13 with appropriate pressure. If the pressure of the knife edges 15 against the guide groove 13 is too great, the reciprocation of the driver 14 will be hampered by too much friction, involving the risk of preventing the smooth operation of the sewing machine. However, the pressure of the knife edges 15 against the guide groove 13 can be adjusted by decreasing the thickness of the dust remover 11 in the middle part thereof. Furthermore, by increasing the thickness of the dust remover 11 adjacent the knife edges 15 at both ends thereof, the dust scraping capacity of the knife edges can be increased.

The invention has an advantage in that the dust remover 11 is easily attachable to and detachable from the driver 14 without difficulty since the dust remover 11 and the driver 14 are fixed together only at the middle parts thereof respectively. That is, since a hollow 17 is formed on one side of the middle part of the dust remover as shown in the drawing and the said hollow 17 is fitted to the extension 19, the dust remover 11 is attachable to and detachable from the driver 14 with greater facility. In this case, the protrusion 18 formed on the other side of the middle part of the dust remover l 1 serves as a knob with which to attach or detach the dust remover 11. Besides the embodiments illustrated in the drawing, a penetrating hole may be provided in the middle part of the dust remover 11, for instance, a screw which penetrates through the said hole being screwed into the hole provided in the middle part of the driver 14.

Since the dust removing operation is conducted by the knife edges at both ends of the dust remover 11 respectively, the width of the knife edges 15 must cover the entire width of the guide groove 13, but the other part of the dust remover 11 may have a smaller width.

What is claimed is:

1. In a sewing machine shuttle mechanism including a semirotary shuttle, a shuttle race having a guide groove therein to receive said shuttle, a driver device mounted for reciprocal motion to drive said shuttle, and a dust remover connected to reciprocate with said driver device to remove dust from said guide groove; the improvement comprising an engaging extension attached to and extending from the outer edge of said driver device at the middle thereof, a head of a larger diameter than said extension attached to the end thereof opposite said driver device, and a pair of spaced protrusions extending laterally from one side of and integral with said dust remover at the middle portion thereof, said extension being positioned between said protrusions and said protrusions and said dust remover being held between said head and said outer edge of said driver device.

2. The improvement claimed in claim 1, wherein said dust remover further comprises an arcuate shape, the outer end, dust removing portions of which are thicker than said middle portion thereof.

3. The improvement claimed in claim 2, wherein the radius of said dust remover is greater than the radius of said guide groove. 

1. In a sewing machine shuttle mechanism including a semirotary shuttle, a shuttle race having a guide groove therein to receive said shuttle, a driver device mounted for reciprocal motion to drive said shuttle, and a dust remover connected to reciprocate with said driver device to remove dust from said guide groove; the improvement comprising an engaging extension attached to and extending from the outer edge of said driver device at the middle thereof, a head of a larger diameter than said extension attached to the end thereof opposite said driver device, and a pair of spaced protrusions extending laterally from one side of and integral with said dust remover at the middle portion thereof, said extension being positioned between said protrusions and said protrusions and said dust remover being held between said head and said outer edge of said driver device.
 2. The improvement claimed in claim 1, wherein said dust remover further comprises an arcuate shape, the outer end, dust removing portions of which are thicker than said middle portion thereof.
 3. The improvement claimed in claim 2, wherein the radius of said dust remover is greater than the radius of said guide groove. 